Glossary of Terms

American National Standards Institute

See ANSI.

ANSI

American National Standards Institute. ANSI, along with the International Organization for Standards (ISO), standardized the COBOL programming language, and continues to promote many other important software standards, such as the ANSI character set. To a large extent, all ANSI COBOL compilers, regardless of which company produces them, should behave similarly, although vendors may provide some proprietary extensions.

API

Application Programming Interface. The interface by which an application program accesses operating system and other services. An API is defined at source code level and provides a level of abstraction between the application and the kernel (or other privileged utilities) to ensure the portability of the code. An API can also provide an interface between a high-level language and lower-level utilities and services which were written without consideration for the calling conventions supported by compiled languages.

Application Programming Interface

See API.

batch file

A text file containing operating system commands that are executed automatically by the command line interpreter. A batch file is called a "shell script" in UNIX, since it is the UNIX shell that includes the command line interpreter. Batch files can be used as a simple way to combine existing commands into new commands.

Binary Large Object

See BLOB.

BLOB

Binary Large Object. A block of data stored in a database, such as an image or sound file. A BLOB has a structure that cannot be interpreted by a database management system but is known only by its size and location.

buffer

An internal memory area used for temporary storage of data records during input or output operations. Most programs keep track of changes in the buffer and then copy the buffer to a disk. Buffers are also used for printing.

client

A computer or program that can download files or data for manipulation from a server. Contrast server. See also network.

data dictionaries

Extended file descriptors that map an application's rows and columns to COBOL records and vice versa. Based on the standard COBOL file descriptors (FDs). See also file descriptor and XFD file.

Data Source Name

See DSN.

directives

Optional comments that you can place into an FD in your COBOL source code to control how the data dictionary is built.

DSN

Data Source Name. An arbitrary name for a group of data files that together form an ODBC database.

Extended File Descriptor

See file descriptor and XFD file.

field

An element of a database record in which one piece of information is stored. Contrast record.

file descriptor

Describes the attributes of a file being accessed, in this case by an ODBC-enabled application, and its associated data record or records. The file descriptor has a special level number, FD, which is the logical file designator. Record descriptions immediately follow the FD, and each record description must start with an 01 Group Level item.

indexed file

In database design, a list of keys (or keywords), each of which identifies a unique record. Indexed files make it faster to find specific records and to sort records by the index field (the field used to identify each record). See also key.

I/O

Input/Output. Communication between a computer and its users, its storage devices, and other computers. The devices the computer uses to do this are called "peripherals."

Input/Output

See I/O.

Julian base date

The Julian date to be used in defining Julian date formats. By default, in AcuODBC, 1900/01/01 is the base date (January 1, 1900). See also Julian date.

Julian date

In integer format, the number of days since a certain date (the Julian base date). For example, if the Julian base date is June 18, 2000 and today's date is July 4, 2000, the Julian date is 16.

key

A value used to identify a record in a database, derived by applying some fixed function to the record. The key is often one of the fields (a column if the database is considered a table with records being rows). Alternatively the key may be obtained by applying some function, for example, a hash function, to one or more of the fields. The set of keys for all records forms an index. Multiple indexes may be built for one database depending on how it is to be searched. See also indexed file.

master DSN

Master Data Source Name. The data source name assigned to a group of multi-company files. Used with the Multi-Company option.

network

Hardware and software data communication systems. Networks are often also classified according to their geographical extent: local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and also according to the protocols used.

ODBC

Open Database Connectivity. Released in 1992, a library of standardized data access functions that gives programmers a way to access and manipulate data in a variety of data sources. Interfaces include Visual Basic, Visual C++, SQL, and the ODBC driver pack contains drivers for the Access, Paradox, dBase, Text, Excel, and Btrieve databases. An application can submit statements to ODBC using the ODBC flavor of SQL, and ODBC then translates these to calls the database understands. ODBC is based on Call-Level Interface and was defined by the SQL Access Group.

ODBC driver manager

Typically provided by Microsoft. Its function is to receive calls from the Windows application, establish which data source driver is being used, call the driver (in this case, the Vision driver, AcuODBC), and load it into memory if it is not already there.

ODBC driver for ACUCOBOL-GT data

Provided by Acucorp, Inc. The function of the ODBC driver for ACUCOBOL-GT data is to receive SQL commands from the ODBC driver manager, and translate them from SQL to the appropriate file I/O using Acucorp's data dictionary files. Known as AcuODBC.

ODCP

AcuODBC Server Control Panel. A graphical interface for Windows used to perform AcuODBC Server functions.

Open Database Connectivity

See ODBC.

query

A user's (or agent's) request for information, generally as a formal request to a database or search engine. SQL is the most common database query language. See also SQL.

record

A group of related fields, or a single field, treated as a unit and comprising part of a file or data set, for purposes of input, processing, output, or storage by a computer. Contrast field.

relational database

A database system in which any database file can be a component of more than one of the database's tables.

server

A computer that makes services, as access to data files, programs, and peripheral devices, available to workstations on a network. Contrast client. See also network.

single-tier

In a single-tier architecture, both the AcuODBC interface and the COBOL data files reside on the same Windows computer, or on a Windows NT/2000 server in a networked environment.

SQL

Structured Query Language. According to specification, the language by which ODBC programs retrieve data. See also query.

Structured Query Language

See SQL.

TCP/IP

Transmission Control Protocol/Internet Protocol. A protocol for communication between computers, used as a standard for transmitting data over networks and as the basis for standard Internet protocols.

Transmission Control Protocol/Internet Protocol

See TCP/IP.

two-tier architecture

An architecture in which the AcuODBC interface resides on the client machine and processing occurs on a remote UNIX or Windows NT/2000 server. The COBOL data files reside on the same remote server.

XFD file

Extended File Descriptors. Data dictionaries are also called extended file descriptors (XFDs) because they're based on the standard COBOL file descriptors (FDs). See also data dictionaries and file descriptor.